What Happens If Your Mini Cylinder Head Gets Cracked?
- July 28, 2022
- MINI Repair
- Posted by Charles Oehmke
- Comments Off on What Happens If Your Mini Cylinder Head Gets Cracked?
The engine’s combustion takes place inside the engine cylinder. The cylinder head, together with the head gasket, seals off the combustion chamber. This cylinder head is the key to controlling airflow in and out of the cylinder and is very important for the internal combustion process to work effectively.
The cylinder heads are usually designed with aluminum. The head is the hottest part of the engine, and aluminum is an excellent thermal conductor. The cylinder head design makes it fragile and could crack if the engine temperature is too hot. While the cracks could only be detected through physical inspection, specific indicators of the problem include overheating and engine misfiring.
Leaving the problem unfixed could spiral into a much larger problem. If you leave the symptoms unattended, the cracked head could cause irreparable engine damage. Keep reading as we explore the symptoms and side effects of a cracked cylinder head in your Mini.
Understanding the Problem
When your MINI engine overheats for an extended period, it increases the engine operating temperature and heightens the cylinder head temperature. The head expands and contracts as the temperature rises, placing it under great thermal stress, leading to its cracking.
While the cylinder is made of cast iron, the cylinder head is usually made of aluminum to help dissipate heat faster and allows for higher compression ratios with reduced risk of engine detonation. The two metals expand and contract at different rates in response to temperature increases. When the two components expand due to high temperature, the cylinder head cracks because it is lighter.
In addition, the head gasket below the cylinder head may also fail due to the heat resulting in the escape of compressed air from the cylinder, thereby increasing the pressure on the head covering the cylinder. This ends up cracking the cylinder head.
Symptoms Of A Cracked Cylinder Head
- White Steam from the Exhaust Pipe: Coolant passages run through the cylinder head. A crack in the cylinder head will lead to coolant leakage into the combustion chamber, where the coolant is burned during the combustion process. This leads to white smoke from the exhaust pipe with a characteristic sweet smell.
- Engine Overheating: Due to the coolant leakage, there will be a drop in the car’s coolant level, which can be noticed when the coolant water temperature is in the red area on your dashboard gauge. You can also watch out for this as it might point to a cracked cylinder head. The drop in coolant level means less coolant circulating through the engine, resulting in an overheating engine.
- Engine Misfiring: A complete combustion requires a correct air/fuel ratio, proper spark, and adequate compression. There’ll be a loss of compression due to the cracked cylinder head leading to misfiring. Also, weak engine performance can point to a cracked cylinder head due to the loss of compressed air and pressure in the cylinder.
Effects of a Cracked Cylinder Head
A cracked cylinder head is not something you want to ignore in your MINI since it isn’t something you can wish away. The cylinder head is primarily designed to provide coverage for the cylinder. Damage to this component means that coolant passing through the cylinder head will leak into the combustion chamber and damage the cylinder.
This damage will cause an irreversible effect in your MINI’s cylinder, requiring you to replace not just the cylinder head and gasket but even more parts to ensure total sealing for proper combustion to occur again. Overall, the damage to parts connected to the head, such as valves, reduces your MINI engine efficiency.
Bring Your MINI To Nikolas Motorsport
Here at Nikolas Motorsport, we understand the inconveniences and hassle that a bad engine can cause. We are dedicated to ensuring your MINI long-term operationality, and we have the proper tools to back up our claims.
We are located in Pontiac, MI, and for several years, we have provided reliable, expert service and welcome drivers of the surrounding communities of Bloomfield Hills, Farmington Hills, Rochester Hills, Royal Oak, and Troy.